“The imposition of Spanish control over Indian societies by church and state in the sixteenth century was greatly assisted by the collapse of [the] native population as a result of repeated epidemics and pandemics, as well as a drop in births… On the mainland, tens of millions [of American Indians] died during the course of the sixteenth century. Europeans brought from Eurasia and Africa a range of infectious diseases, including smallpox, typhus, measles, diphtheria, influenza, typhoid, the plague, pneumonia and more. It is estimated that the native population of Mexico fell from an estimated 17 million at contact in 1519 to between 3.5 million and 1.1 million by the end of the sixteenth century.
Despite these enormous losses in Mexico and Peru and throughout Spanish America, natives still vastly outnumbered Spaniards. To better protect, evangelize and tax native peoples, the crown attempted to implement a policy of segregation, the creation of two ethnic “republics.”… Economic pressures and race mixing undermined this ambitious design.
Nevertheless, a distinctly separate Indian culture survived conquest and colonialism.” – Thomas Benjamin, The Atlantic World: Europeans, Africans, Indians and Their Shared History, 1400-1900 (New York: Cambridge University Press, 2009), p. 174.